/Engine/Source/Runtime/Engine/Classes/EdGraph/EdGraphSchema.h
Allows schema to generate a tooltip (icon & message) when the specified asset(s) are dragged over the specified pin
virtual void GetAssetsPinHoverMessage ( const [TArray](API\Runtime\Core\Containers\TArray)< struct [FAssetData](API\Runtime\CoreUObject\AssetRegistry\FAssetData) > & Assets, const [UEdGraphPin](API\Runtime\Engine\EdGraph\UEdGraphPin) * HoverPin, [FString](API\Runtime\Core\Containers\FString) & OutTooltipText, bool & OutOkIcon ) const